Pre-fabricated building panels have become increasingly popular in the building industry so as to provide a building structure erectable in less time and lower cost than conventional on site construction materials and techniques. Conventional pre-fabricated building wall systems have involved molding techniques which include the teardown of the forming means after the completion of the molding process. The prior art includes many different formations which may be completed at a factory site and shipped to the building construction site for installation. These systems generally offer little flexibility in design and construction. Often the molding techniques employed require the forming structures, i.e. the molds, to be separated from the molded pieces and require a mold or forming structure to be employed for each unit with that forming structure to be disassembled, occasionally destoyed and a new forming structure to be constructed for each piece produced. Not only does such singular forming structure use require the step of forming structure teardown for each building panel formed, resulting in additional expense in time and materials, but also results in reduced productivity of the completed building walls. Other conventional molding methods require the application of mold release materials to the interior walls of the mold structure, yet, in view of the size and weight of the resulting product, still require disassembly of the mold structure. In many instances, different molds must be constructed for the formation of the many varieties in function that must be provided for the completion of the intended buildings. Each change in function for the building wall requires construction of a one-time forming structure dedicated to the production of a single one of the specific function bulding wall. Some building walls must be installed with different footing structures, different framework forms such as including singular and multiple window frames, mounting upon stone beds, concrete footings, caissons, load-bearing frameworks, non-load bearing frameworks, building walls coupled or incorporating joists and joist supports, different types of bearing walls, interior and exterior non-load bearing and load bearing walls, variations in bracing, strapping, spandrel walls, coupling means for joining building wall units and panels together and other functional and constructional variables including variable heights, lengths and thickness.
Another problem encountered with the pre-fabricated wall systems proposed by the prior art is the difficulty in providing access therein for workmen to install in-wall and through-wall services. Further, production of pre-fabricated building walls and panels which offer facility in joining units together in constructing the buildings is another problem encountered with the use of such "prefabs". Integration of inter-related units into the object being constructed also has been more difficult with the available structures and methods presently available to the construction art.
Further difficulty is experienced when considering combinations of different materials such as concrete wall panels with brick and/or brick facing. Such combinations of different construction materials have gained in popularity, where a section of the building being constructed includes concrete exterior walls and, in addition, brick faced sections. Providing pre-fabricated building walls which are combination brick facings and concrete panels is esthetically attractive but difficult and expensive to produce. Means to provide such combinations have not as yet been provided except by the use of embossing a brick pattern upon a concrete surface. The resultant product is far from the esthetic appearance obtained when actual brick is employed. The method and result produced in accordance with the method of the invention enables such contrasting materials to be provided.
Provision of versatile pre-fabricated wall systems and structures at relatively low cost for facile installation and production is a need also not fulfilled by the methods and structures offered by the prior art. Additionally, provision of pre-fabricated cementitious building wall panels which are relatively light in weight yet structurally strong, which can be used as basement walls, foundations, floors and roofs, which are esthetically and physically strong, which can be easily assembled to other of these elements, which are capable of varied attractive appearance, which offer excellent thermal-resistive characteristics and which are capable of multi-level incorporation, likewise has been sadly lacking.
A system that involves fully self-contained pre-fabricated building walls and panels which incorporate the forming structure as a part thereof, yet allows for considerable variation in the their interior, structural content, has not become available despite a long felt need therefor. It is this need that is satisfied with the pre-fabricated building panel system provided by the invention.
Of the plurality of pre-fabricated building walls provided by the prior art, several will be discussed hereinafter to illustrate the state of the art pertinent to the herein described invention. Among these are U.S Pat. Nos. 5,526,629 (Cavaness, Jun. 18, 1996), 5,524,412 (Cori, Jun. 11, 1996), 4,276,730 (Lewis, Jul. 7, 1981), 4,494,353, (Lewis, Jan. 22, 1985, 4,885,884 (Schilger, Dec. 12, 1989), 4,619,032 (Sudrabin, Oct. 28, 1986), 4,930,278 (Staresina et al, Jun. 5, 1990), 4,271,111(Sheber, Jun. 2, 1981), 4,669,240 (Amormino, Jun. 11, 1987), 4,649,682 (Barrett,Jr, Mar. 17, 1987), 4,909,007 (Bodnar, Mar. 20, 1990), 3,885,008 (Martin, May 20, 1975), 4,751,803,(Zimmerman, Jun. 21, 1988), 3,965,635,(Renkert, Jun. 29, 1976), 4,570,398 (Zimmerman, Feb. 18, 1986), 4,605,529, (Zimmerman, Aug. 12, 1986), 3,730,476 (Prichard,Jr. May 1, 1973), 4,934,121, (Zimmerman, Jun. 19, 1990), 5,055,252 (Zimmerman, Oct. 8, 1991), 5,216,863 (Nesssa et al, Jun. 8, 1993) and 5,491,947 (Kim, Feb. 20, 1996).
Cavaness provides a composite building panel comprising a framework formed of a perimetric frame assembly, an array of plural elongate metal studs arranged parallel and spaced within the frame assembly. Each of the metal studs is of elongate C-shaped cross-sectional configuration with middle section wider than a pair of front and rear right angle flanges, the front one of the flanges being embedded in a concrete slab, the concrete slab defining the front of the panel and the remaining portions of the studs defining open spaces or cavities accessible for installation of services, insulation and means for joining one panel to others.
Once the frame assembly is completed, form members are attached about the perimeter thereof defining a mold for receiving the during the pouring of the concrete defining the concrete slab serving as the front of the panel. The floor of the mold is a forming pad adapted to rest upon a planar surface. The mold is oriented horizontally during the pouring of the concrete into the rear of the panel embedding the front portion of the stud, including the front flange thereof. The mold is knocked down (disassembled) when the curing of the concrete is completed.
The free portions of the stud array define cavities to provide for the installation of the requisite services, i.e. plumbing, electrical wiring and insulation. A wall board can be placed over the rear portion of the frame and attached thereto so that the cavities are covered, the wall board functioning as the interior facing wall of installed panel. The panels can be joined end to end by bolting the end studs forming a butt joint. Increased cost is experienced due to the necessity of disassembling the mold after each panel formation. Incorporation of the additional framework components required for varied functional building requirements would be better served if these varied additional framework portions could be incorporated during the molding process common to all panels. Obviously, it would be most economically benficial if the completed panels could be self-contained as well as versatile, i.e. adaptable for plural functions.
The Cori patent is pertinent to the formation of building panels including a framework comprising a frame member having a top and a bottom plate joined by parallel spaced C-configured studs. A mold is prepared and a layer of hardenable cementations material is deposited in a mold. The frame member is laid on top of the cementations layer and a second cementations layer is applied to embed one side of each stud therein, leaving the remaining portion of the frame open. Once a panel is completed, the mold must be dismantled. Although the patentee states that the mold may be reused, it appears that the more prevalent practice is to use the mold as a one-time use either requiring the application of a mold-release by spraying or destroying the mold during the unmolding. The panels produced are half sections used to form a double walled construction, each panel constituting a half-section combined to form various building walls of a building construction. One difficulty is that the panels produced are substantially identical. The use apparently is to form double walls, leaving a space therebetween, with insulation capable of being installed as foam or loose fiber fill.
Lewis '730 provides wall structure modules comprising a plurality of panels of integral sandwich construction with a thickness of insulation molded between two thicknesses of concrete. These panels are formed with tongue and groove configuration along opposite sides, enabling them to be nested together. Spaced steel studs are encased in each exterior panel and a cap channel fits over and along the tops of the nested panels. A small bracket at the top of the panel which is exposed for the attachment of a top plate. A channeled top plate is fitted over the panels of a completed wall section. The steel studs are provided with spaced openings to permit flow through of the concrete in the forming of the panel. A channeled raceway is secured to the panels horizontally for receipt of piping and electrical conduits opening to the interior surface of panel. Teachings are absent which lead to retention of the molds in the finished panels.
Lewis '353 teaches the provision of load bearing wall sections having frame units formed of metal sections providing interconnected longitudinal frame members and interconnecting means defining a rectangular skeletal frame having an infill of rigid insulation. The metal sections are studs having passageways for reinforcing bars to pass through. The studs are C-shaped with flanges carrying said passageways. Two layers of insulation are fitted along the studs. Although the pouring of concrete to embed a portion of the studs and insulation assembly is taught, there is no disclosure indicating how the concrete is poured, nor do the drawings show the use of concrete, except as a footing (FIG. 13 thereof) to which the panel is bolted. The entire framework is not enclosed in concrete.
Schilger provides a panel functioning as a building component. The panel comprises plural spaced C-shaped metal studs coupled to an rigid insulation board by projecting lugs, the lugs being embedded in a sprayed on concrete layer. A wire mesh reinforcing layer is applied to the concrete layer. An embodiment is illustrated in which the lugs projecting from the inner flanges of the studs are embedded in concrete, and, as well provision is mode to join adjacent panels via butt joints in which the lugs are embedded in a concrete floor. Concrete is poured into a horiztontally oriented form and the beam and formwork assembly is placed upside down in the wet concrete, the wire mesh sinking into the wet concrete until the panel surface engage the wet concrete. The formwork panel, i.e. the rigid insulation board to which the studs are secured by the lugs remains as a part of the final construction but the horizontally oriented form functions as a mold and is detached once the curing of the concrete is completed.
Sudrubin is directed to a thin reinforced wall formed of sprayed concrete and short lengths of glass fibers as a preformed outer shell intended to be exposed to the atmosphere. An inner load supporting structure is secured to the inner surface of the outer shell, said load supporting structure being formed of a metal frame aligned with the inner surface of the outer shell and spaced metal studs. The studs are flanged channel members seated in on their inner flanges in spaced array across the inner surface of the outer shell, each mid-portion of the studs carrying spaced cut-outs to permit concrete to flow therethrough and oriented perpendicular to said inner surface. Plural wire matrices are permanently applied to the inner surface of the outer shell in spaced array adjacent the studs, and cementations material is applied thereover to form raised patches.
A fixture similative of the frame and stud array but having a lower flange thereof of a width generally equal to the width of the patches, is employed as a guide for the installation of the studs and frame are correctly installed.
Concrete is poured into the fixed arrangement of the frame and stud array with the flex-ties properly installed. Other walls may be formed substituting sheet insulation installed within the stud/frame before the concrete is introduced. After the concrete has cured, the resulting panel is tipped along its edge and installed as the building wall.
Finished panels thus are installed but no provision was made for installation of services, etc. after the panels have been erected installation of the load supporting structure. Plural flexible ties are attached to the patches at one of their ends and secured to the respective studs, said ties functioning as "tie-downs". The patches are fixed in position by spraying same with a glass-fibrous material or concrete, and the other of the flexible tie-ends are secured to the wire matrice (and patch), holding the stud (studs) in properly orientated condition.
Staresinna et al provides a composite building panel comprising a slab of cementations fiber reinforced material and a stud framework keyed thereto. The studs are of C-configuration with a flange abutting the inner wall surface of the slab and a plurality of tabs are formed in the flange which project downwardly to key the stud in retaining the slab in the cementations layer. Each stud is formed with a center portion comprising a series of trusses. The slab had been formed by pouring the hardenable material into a suitable casting form, which may be provided with a decorative veneer or which may be discarded. Again the result is a decorative wall panel, but one which apparently lacks versatility.
Sheber does not incorporate metal studs of any form but rather provides a building panel having a wall section, a plurality of concrete reinforcing ribs disposed along an inner surface of the wall section and a plurality of nailing strips anchored along an outermost surface of each reinforcing rib. Reinforcing bars are disposed in the reinforcing ribs. The outer surface of the wall section contains an embossed decorative pattern. Interior wallboard is attached by nails to the nailing strips. The basic wall section is formed in a mold, the decorative formations are rolled onto the concrete surface, the concrete cured and the embossed panel is separated from the mold. The provision of variations in framing structure and the accommodation of installation of services is not considered.
Amormino teaches the formation of a precast concrete building panel formed of inner and outer panel elements with a steel wire mesh embedded through each panel element. A series of laterally spaced continuous steel rod trusses are interposed between the panels and at right angle thereto. An insulating panel is bonded between and overlying the interior side of the panels. Pairs of aligned panels and related corner panels are interconnected by a concrete column poured in situ between adjacent panels. The spaces between the panels function as an air barrier zone. The wire mesh reinforcement does not function as a supporting element. The finished wall panel is formed in a mold and the mold is separated from the finished wall panel after curing of the concrete.
Barrett,Jr. is directed to the provision of a prefabricated building panel which may be filled with a hardenable material which need not have substantial load-bearing characteristics. The panel has a metal load-bearing framework formed of C-shaped cross section placed across the central opening. Means for reinforcement, lifting means, receptacle boxes and interconnecting conduit for said boxes and other service installing means can be installed as desired. Insulating material can be installed in the central opening. The frame is placed in a horizontal orientation on a horizontal surface, a transversely extending lip is formed around both sides of frame. Concrete is poured into the frame, forming a first layer embedding the lower portion of the studs. Insulating material is placed on the first layer and a second concrete layer is poured thereupon. After the concrete layers are hardened, the lip is removed, the lip having functioned as a retainer--a forming mold.
The reinforcing bars can be placed across the central opening of the frame and can be embedded in another concrete poured, another temporary retainer member being installed and after curing, removed. Barrett,Jr. uses these temporary forms for other retaining purposes, and then, teaches the steps of removing these forms once the material retained was hardened.
Bodnar utilizes the stud truss type configuration taught by Staresina et al which has a locking strip defining an acute angle with the first surface of a concrete slab with the flange from which the locking strip is formed being embedded in the cast material. A mold is utilized and discarded after cure of the cast material. The cast "slab" is formed of two layers with wire mesh embedded therein.
Martin also teaches the formation of a frame, here preferably formed of spaced wood studs across the opening of the frame. A retaining mold surrounds the frame and concrete is poured into the mold. The frame can be introduced into the mold prior to the pouring of the concrete or after the concrete had been poured. The mold is removed after the concrete had been cured.
Zimmerman '529 provides a method of forming a prefabricated concrete wall of the type forming a strong, insulated basement wall off-site for later installation. This method employes precast concrete studs with steel reinforcing rods cast thereinto. As the studs are cast, a wood strip is cast onto one elongate narrow edge which eventually functions as a support for fastening dry wall. Fasteners are cast into the opposite edge which will hold the exterior surface. The method comprises orienting the concrete studs horizontally in a frame with the edges exposed and fasteners protrude from the edges, laying rigid insulation within the frame on top of the said edges with the fasteners piercing the insulation, pouring concrete into the enclosure defined by the frame covering the rigid insulation and the fasteners and allowing the concrete to set. Once set, the finished structure is removed from the frame. According the frame must be constructed, placed and then removed . . . not forming a part of the finished structure. The concrete studs are employed for vertical height and strength and cast concrete is applied for sealing and waterproofing the exterior wall.
Zimmerman '803 also forms a prefabricated building wall employing concrete studs. Precast concrete studs with fasteners protruding from one edge thereof is oriented in a horizontal plane. Rigid sheet insulation is attached to the outside of the studs and wire mesh is laid upon the sheet insulation. Concrete is poured onto the insulation, the wire mesh and the protruding fasteners. Top and bottom beams bonded to the studs are formed at the same time as the outer concrete surface is formed. The formation takes place in a mold which is removed after the concrete is cured. The resulting wall is a single integral structure transportable to the site of construction. The result is a fully embedded concrete unit as the prefabricated panel.
Renkert employs a mold form laid horizontally and places bricks at the indicated reception areas of the mold form and applies a layer of a fibrous cementations mixture to the spaced between the bricks and over the tops of the bricks. A lattice work consisting of steel studs arranged in a crossed lattice formation is laid onto the still soft cementations mixture. A resinous insulating material is foamed in situ in the mold cavities formed between the lattice work elements and a finish coat of cementations material is spread over the resinous insulating material by troweling or spraying. After the materials have finshed curing, the mold form is removed. The resulting panel has an outer brick surface, and is insulated. No provision is made for installation of services.
Prichard,Jr provides a unitized reusable form for generally vertical concrete surfaces including plural form panels and metal supporting studs having associated fastening devices. The studs are provided with spaced holes to accept headed snap ties releasably maintained by fastening wedges communicating between the snap tie and the stud. The mold is defined by a pair of spaced wooden sheets retained by vertically oriented bars mounted on opposite sides of the wooden sheets by seating on a cross bar (or stud) array of the exterior studs, said studs carrying clips and waler supports for cross-beams or cross studs. Concrete filler is introduced between the pair of the vertically oriented wooden sheets from the upper end thereof to fill the spaces therebetween.
Zimmerman '398 utilizes precast concrete studs to build a framework of the vertical walls of a basement, rigid sheet insulation being attached to the outside of the concrete studs and wire mesh is attached to the insulation. Concrete is sprayed onto the insulation and wire mesh to form a continuous waterproof outer surface. The forming of such basement wall is performed on the construction site.
In contrast to Zimmerman '398, Zimmerman '121 provides a prefabricated concrete wall structure formed of concrete studs having integrated, interconnecting reinforcing structure comprising a horizontal beam within the stud and cross bars connected to said beams extending inward of the openings of the framework and adapted to be connected ones to the others to define an integrated network. The provision of a shear connector which interconnects the reinforcing rod in the vertical stud to the rods in the top and base beams of the frame. An assembly jig is formed and the framework is formed therein. The jig includes stud molds from which the skeleton of the wall section is assembled.
The studs include holes therethrough at various locations along their length to permit electrical cable and plumbing pipes to pass therethrough after the wall section is installed as a part of a building. In constructing the wall section, the reinforcing rods are arranged and wired together. The stud molds are oriented perpendicular to support members within which concrete is poured. The required network of reinforcing rods is assembled with the stud molds located so only one is located adjacent to the frame member, the internal stud molds of the skeletal framework extending fully between the support members. Then three successive layers is applied to the stud mold framework. The first layer is rigid insulation laid across the entire framework except for the tops of the stud molds and the support members. The next layer is wire mesh to reinforce the to be formed concrete layer. The wire mesh is laid across the entire insulation layer. The final layer is the concrete covering everything. After the concrete hardens, the resulting wall section is lifted from the assembly jig.
Zimmerman '252 is directed to a method of constructing a prefabricated wall structure including the steps of orienting interspaced stud molds, with channel shaped cross section configurations and edges defining an open portion of channel shape, in a horizontal configuration within a framing means so that the edges of the stud molds form uppermost parts of the stud molds and are located within an essentially horizontal plane within the framing means; orienting two parallel support members configured like the above mentioned stud molds but with channel shaped cutouts in one wall of the channel configuration at opposite ends of the stud molds so that the stud molds adjoin the support members at said channel shaped cutouts and the edges of the support members are uppermost and are located in the horizontal plane of the edges of the stud molds. Next, layers of rigid insulation panels are laid within the framing means on top of the edges of the stud molds and support members but not covering the open portions, whereby to form a continuous surface within the framing means. Lastly, concrete is poured into the enclosure formed by the framing means to form the prefabricated wall structure when cured. Thereafter, the wall structure is removed from the framing means, i.e. the "mold".
Nessa et al and Kim each employ interlocking metal panels arranged to form a form-fil wall which is filled with concrete and the form becomes part of the finished wall. Nessa et al provides a formwork including plural interconnectable disposable generally cylindrical metal elements, each consisting of an elongated, thin-walled cylinder-shaped element adapted to be coupled to a next like element, the elements being vertically oriented and filled with concrete forming a row of fused concrete columns. The forms can remain as the external surfaces or can be removed. Kim provides a form-fil concrete wall assembled from a plurality of connected metal wall panels but not formed into cylindrical columns but connected to define a continuous wall having inner and outer panels, concrete being used to fill the spaces between the panels. The form-fil panels are retained to form the finished siding of the resultant wall. The cross-section of the resultant wall is octagonal.